Canon IPF 750 nozzle check problem

[jesse38]

Hi everyones, I noticed today that my printing were a bit fade on the black colour so I started a nozzle check verification and ... surprise: one of the block (Black) is half missing ... I changed the head already and it seems to do it again ... Since I have a a pattern with:

Black Black Black
//// Black Black

Yellow Red Blue
Yellow Red Blue

It seems like an electrical problem ... And infortunately not a head issue ... Is anyone had encounter this problem before ?

 

[kdsdata]

I had a similar problem, not with the IPF-750, but with an i9900. That's why I wound up upgrading to my Pro-100. It started the same way. One colour started missing lines, then some more, and then a second colour started similarly. I did the nozzle check, replaced carts, with no improvement. I do remember that the results were not consistent. The missing lines were not always in the same place. That through me for a loop.

In my opinion, from the symptoms you mention, I would say it is electrical. You can visually check the flat cable, but beginning-breaks in the wires are very hard to see. It's very difficult to uplug the cable ends to clean them, takes a printer disassemble to do that, and may on your model not be possible if the cable end is somehow sealed**. You can remove the carts and remove the print head (if you are not familiar with this, watch YouTube videos elsewhere for this procedure). Then clean the contacts. I use a soft nylon eraser for this. First, rub the eraser on some clean paper to get any greasy film off (even fingers will leave such a greasy film). DO NOT use a pink erase, it's too abrasive. Brush the contacts so you do not bend any wires. And wipe the crumbs off with a soft clean cloth. DO NOT use a vacuum cleaner, the static electricity can damage the print head, or inwards the motherboard.

I did all the above things, but in the end nothing worked for my i9900 to make it behave properly.

The problem could even be further in, such as the motherboard. To prove that possibility on my i9900 I did disassemble my i9900 to get to the cable ends (a messy job, and most importantly, it seemed like a one-way trip, meaning no likelihood of a successful re-assemble). The cable checked out fine, so I surmised a motherboard fault, and went out to buy the Pro-100. At that time I already had my eyes on the Pro-100, so I am sticking with my excuse to upgrade.

If I remember correctly, the flashing orange light did indicate a motherboard fault, but in the detailed service instruction it also said that it could be a "misinterpretation" of a signal from the print head. Meaning that in severe cases the flashing orange light is less than useful. Via Google, I have not been able to again find the said service instruction.

I am of the opinion that a changing check pattern is the best symptom for an electrical fault like a broken connection, but that would likely not be the case for a motherboard fault. The broken connection is more prone to changes due to movement, where the motherboard fault is more affected by board temperature, where the changes take place much slower.

I sign off by wishing you better luck.

** The idea to unplug the cable ends comes from the latest issues with tablets that have the connection problem. I thought of this a few years back in regards to my i9900, but without much success.

 

[jesse38]

Thanks a lot for your feedback from the other side of the atlantic ... Strangely enough it seems to print not that bad with one black block ... it is a bit fade though ...

 

[kdsdata]

It is neat to see where all the communications originate.
Seems to makes the world a smaller place.
That's why I am (sort of) in favor of showing locations.
But of course it's everyone personal decision.

All the best in regards to your printer problems.

 

[berttheghost]

Check the electrical contacts on the print-head and mating connectors to ensure that they are dry and grease-free. Finger oils are sufficient to increase electrical resistance, so don't touch the contacts wirh your fingers. Use a cleaner specifically sold for cleaning electrical contacts. Hope this helps. good luck.

 

[PeterBJ]

Maybe a service manual would be helpful? You find user and service manuals for the IPF750 here: https://www.manualslib.com/i/ipf750.html